<button id="btn">获取event对象</button>
<script>
  var btn = document.getElementById('btn');
  btn.onclick = function(e) {
    var event = e || window.event;    // 获取事件对象的兼容处理
    console.log(event);
  };
</script>
<p>
  <a href="file:///C:/Users/rise/Desktop/%E9%A6%96%E9%A1%B5/default/08.html">返回</a>
</p>
